We use Optical Character Recognition (OCR) during our scanning and processing workflow to make the content of each page searchable. You can view the automatically generated text below as well as copy and paste individual pieces of text to quote in your own work.
Text recognition is never 100% accurate. Many parts of the scanned page may not be reflected in the OCR text output, including: images, page layout, certain fonts or handwriting.
Manufacture of Magnetic Recording Materials
' EDWARD SCHMIDT and ERNEST W. FRANCK
This paper describes in a general way the basic techniques employed in the manufacture of magnetic recording materials. Quarter-inch tape is first discussed, then full-width magnetic film and striping. Last is a brief prognostication of coming trends.
HILE MUCH has been written on the it of magnetic recording, little has ipeared on the methods and problems ( manufacturing the recording media. >.ice the introduction of the first magbtic recorder in the 1890's, many types id forms of magnetic materials have Hien tried. Today, however, the bulk
< all work in the field is on nonhomojneous mediums, namely, those prouced by the application of iron oxide jwder to nonmagnetic base materials. |iis paper discusses the methods used I Reeves Soundcraft to produce plastic
< paper base recording tape, and magpie film products used in the motion future field.
I In a paper and demonstration at the llciety's Convention at Lake Placid, in
Resented on October 18, 1951, at the jciety's Convention at Hollywood, by [ward Schmidt, who read the paper, and nest W. Franck, Magnetic Materials v., Reeves Soundcraft Corp., Springdale, m.
is paper was first received January 10, >2. and in revised form on November 26, 152!)
October 1950, we briefly reported on the development of 16mm striping.1 The facilities used in this work have now been vastly expanded to include both 35mm and 8mm films. Two years of commercial experience have shown up a number of problems which are also discussed.
Base Materials
The German plastic tape products were coated on a vinyl type base material,2 and had good tear and shrink characteristics but very poor temperature stability. Vinyl base cannot stand the normal rigors of heat in regular use. Calendered kraft paper has been used to some extent, but suffers from very low tear resistance and a poor signal-to-noise ratio due to paper's fibrous structure. The bulk of present day tape products is coated on cellulose acetate sheeting, 1.5 mils thick. This sheeting is manufactured in quantity as a standard item by three large American companies, Celanese Corp., Du Pont and Eastman Kodak Co., and is available in adequate quality and quantity. Since the moisture characteristics, swell and shrink
April 1953 Journal of the SMPTE Vol. 60
453